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Configuring TWAMP on MX, M, T, and PTX Series Routers and EX4300 Series Switches

Two-Way Active Measurement Protocol (TWAMP) support and configuration varies for hardware platform, physical interfaces, or virtual physical (services) interfaces. To enable some features, you configure TWAMP under the real-time performance monitoring (RPM) stanza. However, support for RPM is not always an indicator of TWAMP support on a particular combination of platform and line card. The time stamps used in RPM and TWAMP added in different places, depending on the hardware configuration.

For example, different hardware components perform timestamping either in the Routing Engine, the Packet Forwarding Engine, or the line card such as a Multiservices Physical Interface Card (MS-PIC), Multiservices Modular Interface Card (MS-MIC), Multiservices Modular PIC Concentrator (MS-MPC), or Multiservices Dense Port Concentrator (MS-DPC).

Starting in Junos OS Release 19.2R1, the Two-Way Active Measurement Protocol (TWAMP) is supported on PTX Series routers. The destination interface si-x/y/z attribute, which is meant for enabling inline services, is not supported on PTX Series routers for TWAMP client configurations. Starting in Junos OS Release 21.1R1 for PTX Series and MX Series routers, we support TWAMP Light, as defined in Appendix I of RFC 5357, which defines a light version of the TWAMP protocol, a stateless version of TWAMP where test parameters are predefined instead of negotiated. All test packets received by the server on a test port are reflected back and forgotten right away. For Junos OS, TWAMP is configured at the [edit services rpm twamp] hierarchy level.

Starting in Junos OS Evolved 20.3R1, TWAMP is supported on PTX10003 routers. Starting in Junos OS Evolved Release 21.1R1, TWAMP is supported on the PTX10001-36MR, PTX10004, and the PTX10008 (with the JNP10008-SF3 and either the JNP10K-LC1201 or JNP10K-LC1202-36MR line card) routers. For Junos OS Evolved, TWAMP is configured at the [edit services monitoring twamp] hierarchy level.

Table 1 shows the relationship between RPM client and server support, TWAMP client (with the control component) and TWAMP server (with the responder component) support, and the hardware that performs timestamping.

Table 1: TWAMP Feature Support and Hardware

TWAMP Feature Support

Routing Engine Timestamp

MS-PIC/MS-DPC Timestamp

MS-MIC/MS-MPC Timestamp

Packet Forwarding Engine (ukernel) Timestamp

Packet Forwarding Engine (LU) Timestamp (si- interface)

RPM Client

Yes

Yes

Yes

Yes

No

RPM Server

Yes

Yes

Yes

Yes

No

TWAMP Client

No

No

No

No

Yes

TWAMP Server

No

Yes

No

Yes (No responder configuration needed)

Yes

Note:

Support for the services interfaces (sp-, ms-, and si- interfaces) are all slightly different.

For more information on TWAMP, see RFC 5357, A Two-Way Active Measurement Protocol (TWAMP).

Configuring a TWAMP Server

With the exception of physical interfaces, TWAMP server configuration for Junos OS requires the following minimum configuration at the [edit services rpm twamp] hierarchy level:

Starting in Junos OS Release 21.1R1 for PTX Series and MX Series routers, you can configure light control for the server (managed control is the default). TWAMP server configuration for light control requires the following minimum configuration at the [edit services rpm twamp] hierarchy level:

For Junos OS Evolved Release 20.3R1 and later on the PTX10003 router, and for Junos OS Evolved Release 21.1R1 and later on the PTX10001-36MR, PTX10004, and the PTX10008 (with the JNP10008-SF3 and either the JNP10K-LC1201 or JNP10K-LC1202-36MR line card) routers, you can configure either managed or light control for the server. TWAMP server configuration for managed or light control requires the following minimum configuration at the edit services monitoring twamp hierarchy level, assuming you use the default port for TWAMP (862):

You cannot use the following addresses for the client-list source IP address used for probes:

  • 0.0.0.0

  • 127.0.0.0/8 (loopback)

  • 224.0.0.0/4 (multicast)

  • 255.255.255.255 (broadcast)

You can configure more than one client, and you can change the TWAMP listening port as long as the change is coordinated with the TWAMP client.

For si- or sp- services interfaces, TWAMP server configuration requires the following statements at the [edit interfaces service-interface-name] hierarchy level:

Note:

You cannot configure the TWAMP server on unit 0 of a services interface. If you try, you will receive a configuration error.

To configure a TWAMP server on an inline services (si-) interface, configure the amount of bandwidth reserved on each Packet Forwarding Engine for tunnel traffic using inline services by including the bandwidth (1g | 10g) statement at the [edit chassis fpc slot-number pic number inline-services] hierarchy level. Specify the service PIC (sp-) logical interface that provides the TWAMP service by including the twamp-server statement at the [edit interfaces sp-fpc/pic/port unit logical-unit-number family inet] hierarchy level.

The twamp-server statement is not required for physical interface TWAMP server configuration.

Many other TWAMP server parameters are optional. See the TWAMP server configuration statements for details.

Configuring a TWAMP Client

For Junos OS, to configure the TWAMP client service, include the client statement and related parameters at the [edit services rpm twamp] hierarchy level. For Junos OS Evolved, include the client statement and related options at the [edit services monitoring twamp] hierarchy level.

There are many options available for TWAMP client configuration. See the configuration statement topics and examples for details.

The si- interfaces are virtual physical interfaces that respond as a TWAMP server. However, you can also configure services interfaces to act as the TWAMP client, which performs the TWAMP controller role.

To configure a services interface as a TWAMP client, you configure the service parameters and the service interface as a TWAMP client.

To configure the TWAMP client services interface, include the rpm twamp-client statement at the [edit interfaces si-interface-name] hierarchy level:

Note:

You cannot configure the TWAMP client on unit 0 of a service interface. If you try, you will receive a configuration error.

Release History Table
Release
Description
19.2R1
Starting in Junos OS Release 19.2R1, the Two-Way Active Measurement Protocol (TWAMP) is supported on PTX Series routers.